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    Biosorption of Heavy Metals (Cd2+, Cu2+, Co2+, and Mn2+) by Thermophilic Bacteria, Geobacillus thermantarcticus and Anoxybacillus amylolyticus: Equilibrium and Kinetic Studies
    (Taylor & Francis Inc, 2013) Ozdemir, Sadin; Kilinc, Ersin; Poli, Annarita; Nicolaus, Barbara
    Two strains of thermophilic bacteria, Geobacillus thermantarcticus and Anoxybacillus amylolyticus, were employed to investigate the biosorption of heavy metals including Cd2+, Cu2+, Co2+, and Mn2+ ions. The effects of different biosorption parameters such as pH (2.010.0), initial metal concentrations (10.0300.0mg L-1), amount of biomass (0.2510g L-1), temperature (3080 degrees C), and contact time (15120min) were investigated. Concentrations of metal ions were determined by using an inductively coupled plasma optical emission spectrometry (ICP-OES). Optimum pHs for Cd2+, Cu2+, Co2+, and Mn2+ biosorption by Geobacillus thermantarcticus were found to be 4.0, 4.0, 5.0, and 6.0, respectively. For Anoxybacillus amylolyticus, the optimum pHs for Cd2+, Cu2+, Co2+, and Mn2+ biosorption were found to be 5.0, 4.0, 5.0, and 6.0, respectively. The Cd2+, Cu2+, Co2+, and Mn2+ removals at 50mg L-1 in 60min by 50mg dried cells of Geobacillus thermantarcticus were 85.4%, 46.3%, 43.6%, and 65.1%, respectively, whereas 74.1%, 39.8%, 35.1%, and 36.6%, respectively, for Anoxybacillus amylolyticus. The optimum temperatures for heavy metal biosorption were near the optimum growth temperatures for both strains. Scatchard plot analysis was employed to obtain more compact information about the interaction between metal ions and biosorbents. The plot results were further studied to determine if they fit Langmuir and Freundlich models.
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    Öğe
    Resistance and bioaccumulation of Cd2+, Cu2+, Co2+ and Mn2+ by thermophilic bacteria, Geobacillus thermantarcticus and Anoxybacillus amylolyticus
    (Springer, 2013) Ozdemir, Sadin; Kilinc, Ersin; Nicolaus, Barbara; Poli, Annarita
    In this study, bioaccumulation and heavy metal resistance of Cd2+, Cu2+, Co2+ and Mn2+ ions by thermophilic Geobacillus thermantarcticus and Anoxybacillus amylolyticus was investigated. The bacteria, in an order with respect to metal resistance from the most resistant to the most sensitive, was found to be Mn2+ > Co2+ > Cu2+ > Cd2+ for both G. thermantarcticus and A. amylolyticus. It was determined that the highest metal bioaccumulation was performed by A. amylolyticus in Mn2+ (28,566 mu g/g dry weight), and the lowest metal bioaccumulation was performed by A. amylolyticus in Co2+ (327.3 mu g/g dry weight). The highest Cd2+ capacities of dried cell membrane was found to be 36.07 and 39.55 mg/g membrane for G. thermantarticus and A. amylolyticus, respectively, and the highest Cd2+ capacities of wet cell membrane was found to be 14.36 and 12.39 mg/g membrane for G. thermantarcticus and A. amylolyticus, respectively.
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    Öğe
    Thermophilic Geobacillus galactosidasius sp nov loaded ?-Fe2O3 magnetic nanoparticle for the preconcentrations of Pb and Cd
    (Elsevier Sci Ltd, 2016) Ozdemir, Sadin; Kilinc, Ersin; Okumus, Veysi; Poli, Annarita; Nicolaus, Barbara; Romano, Ida
    Thermophilic bacteria, Geobacillus galactosidasius sp nov. was loaded on gamma-Fe2O3 magnetic nanoparticle for the preconcentrations of Pb and Cd by solid phase extraction before ICP-OES. pH and flow rate of the solution, amounts of biosorbent and magnetic nanoparticle, volume of sample solution, effects of the possible interferic ions were investigated in details. Linear calibration curves were constructed in the concentration ranges of 1.0-60 ng mL (1) for Pb and Cd. The RSDs of the method were lower than 2.8% for Pb and 3.8% for Cd. Certified and standard reference samples of fortified water, wastewater, poplar leaves, and simulated fresh water were used to accurate the method. LOD values were found as 0.07 and 0.06 ng mL (1) respectively for Pb and Cd. The biosorption capacities were found as 34.3 mg g (1) for Pb and 37.1 mg g (1) for Cd. Pb and Cd concentrations in foods were determined. Surface microstructure was investigated by SEM-EDX. (C) 2015 Elsevier Ltd. All rights reserved.
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    Öğe
    Thermophilic geobacillus galactosidasius sp. nov. loaded fe2o3 magnetic nanoparticle for the preconcentrations of pb and cd.
    (Bioresource Technology, 2016) Özdemir, Sadin; Kılınç, Ersin; Okumuş, Veysi; Poli, Annarita; Nicolaus, Barbara; Romano, Ida
    Thermophilic bacteria, Geobacillus galactosidasius sp nov. was loaded on c-Fe2O3 magnetic nanoparticle for the preconcentrations of Pb and Cd by solid phase extraction before ICP-OES. pH and flow rate of the solution, amounts of biosorbent and magnetic nanoparticle, volume of sample solution, effects of the possible interferic ions were investigated in details. Linear calibration curves were constructed in the concentration ranges of 1.0–60 ng mL_1 for Pb and Cd. The RSDs of the method were lower than 2.8% for Pb and 3.8% for Cd. Certified and standard reference samples of fortified water, wastewater, poplar leaves, and simulated fresh water were used to accurate the method. LOD values were found as 0.07 and 0.06 ng mL_1 respectively for Pb and Cd. The biosorption capacities were found as 34.3 mg g_1 for Pb and 37.1 mg g_1 for Cd. Pb and Cd concentrations in foods were determined. Surface microstructure was investigated by SEM–EDX.